Synchronous driving device



' 1929- s. A. MURDOCK I SYNCHRONOUS DRIVING DEVICE Filed July 30, 1925 5 Sheets-Sheet W 6 U 4 f M/ n my 5 e F r f w w w 0 W1 '//////////4 I; ZY/IA Nov. 19, 1929. s, A, oc 1,736,323

SYNCHRONOUS DRIVING DEVICE Filed July 30, 1925 5 Sheets-Sheet 2 u 0 57 /2 L 38 E 42 l [I I n Nov. 19, 1929. s. A. MURDOCK 1,736,323

SYNCHRONOUS DRIVING DEVICE Filed July 30, 1925 3 Sheets-Sheet 3 Ely.

45 I nize a motion picture camera or projector,

Patented Nov. 19, 1929 UNITED. STATES PATENT OFFICE SIDNEY A. MURDOCK, OF "LOS ANGELES, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, OF ONE-HALF TO ORLEANDO E. KELLUM, OF LOS ANGELES, CALIFORNIA, AND ONE-HALF TO MARY G. KELLUM, F LOS ANGELES, CALIFORNIA SYNCHRONOUS DRIVING DEVICE Application filed July 30-, 1925. Serial No. 46,982.

ered in its broader aspects, the invention is not limited to any specific application as regards the particular machines or parts to be synchronized, it is especially well adapted for use in combination with a motion picture machine (for instance, a camera or projector) and a phonograph disk (or the mechanism for rotating said disk) during the production or reproduction of talking pictures where constant synchronism between the controlling and dependent machines is a necessity.

In explaining the application of the invention, I have chosen to designate a phonograph, or a record carried thereby, as the controlling device, and an electrically driven o projector or kinetograph as the dependent mechanism, but it will be understood this is merely a choice of convenience arid is not to be construed as many way limiting the invention. An understanding of the particular application here described will lead readily to an understanding as to the applicability of the invention to other mechanisms.

'Heretofore, synchronizing devices have either been entirely self-contained units or have been of a nature to necessitate incorporation of certain of their elements in the mechanism of astandar'd phonograph, requiring considerable alteration of and work on such mechanism. Consequently, talking picture production and reproduction has been limited to the professional field.

Therefore, in addition to the general object of providing an efficient device for rendering possible the extremely fine degree of synchronism requisite tothe'production and reproduction of talking pictures, it is one of the principal objects of the invention to provide a device capableet attachment to a phonograph disk (either blank or record) itself, thereby making it possible to synchrowith said disk as operated by any phonogra h, mechanism.- Thus, irrespective of ma e of phonograph, anyone may apply my; device to a properly prepared disk and produce and reproduce talking pictures without in any way altering or attaching to the drive mechanism of the phonograph. I

The kinetograph attachment here shown and described is adapted for application to a particular make of home projector, without in any way altering the projector mechanism. However, it is to be understood this is not to be construed as limiting the invention, considered in its broader aspects, to such a specific application. a

Both projector and disk attachment are of a nature to be quickly and easily applied to and disconnected from kinetograph and phonograph mechanisms, so one may readily switch from independent use of the mechanisms to synchronous connection or vice versa.

Other objects and novel features will be more readily understood from consideration of the following detailed description, in which Fig. 1 illustrates an embodiment of my invention as applied to a phonograph and proector; I

V Fig. 2 is a fragmentary plan section on line 2-2 of Fig. I;

Fig. 3 is a fragmentary-section on line 3-3 of Fig. 2;

Fig. 4 is an enlarged, fragmentary plan view of the projector casing showing a preferred means for attaching a supporting member thereto;

Fig. 5 is a section, partly in elevation, on line 5-5 of Fig. 4;

Fig. 6 is a section on line 66 of Fig. 5;

Fig. 7 is a wiring diagram illustrating how the projector anddisk attachmentelements are wired.

Fig. 8 is an enlarged plan view of the disk attachment portion of my device applied to a suitably prepared sound record;

Fig. 9 is a detached plan view of a record prepared to take my attachment;

Fig. 10 is an enlarged end elevation of the projector attachment as viewed from the left ofFig. 1;

Fig ll is an enlarged section, partly in in elevation, on line 11-11 of Fig. 8;

Fig. 12 is a reduced section on line 1212 of Fig. 11;

Fig. 13 is a section on line 1313 of Fig. 10;

Fig. 14 is a section on line 14-14 of Fig. 13

Fig. 15 is a section on line 1515 of Fig. 14; and

Fig. 16 is a section, partly in elevation, on the broken line 16-16 of Fig. 13.

First, I will generallydescribe the operating principles of a synchronizing system of which the device here disclosed may be a part, whereupon the reasons for certain provisions and arrangements being made in said 1 device will become apparent. I have chosen to illustratea system involving the combination of a projector, a record on a phonograph, an electric motor, means operated by the disk for controlling the occurrence or regular, successive motorimpulses, and driving connective means between the motor and projector, the

driving means preferably being such that the motor impulses occur in evenly timed synchronism with the exposure or exposure cycles of the projector.

A rotary armature type motor is illustrated, its commutator being driven by the motor through the projector, and the operating circuit. to the motor commutator including a commutator controlled by the phonograph record. Thus the delivery of operating cur-. 'rent through the motor commutator to the impulse elements of the motor is controlled by the record (irrespective of the particular nature of the mechanism driving it) and the connective means and projector are-so arranged that the motor impulses occur in evenly timed synchronism with the oxposure operations or cycles of the projector.

' In the drawings, K represents a projector; M an electric motor adapted to operate on either direct or alternating current and to dive the rojector through shaft S which represents t e driving connective means between the projector and motor. The device operated by record R on phonograph P for controlling the occurrence of regular successive motor impulses, which device embodies the present invention, includes a disk attachment A and a projector attachment B. Attachment A includes a commutator adapted to be put in circuit with the motor commutator, the latter being a part of attachment B. The segments of the two commutators'are interconnected by wires in cable C; the motor commutator, driven through thelprojector, preferably being adapted to break the motor circuit in phase with the intermittent movement at least once'during each alternate cycle of rojector operation. Tlie commutator in attac ment A and driven by the record is adapted to reclose the motor circuit after each break therein; v

In order to point out more clearly certain I characteristics of the system and'attachments,

convenient to assign certain drive ratios, speeds, numbers of commutator segments, etc., but these are not to be considered as in any way limitative on the invention. However, I will first describe the structural char .adapted to be driven from a usual motor (not shown) through vertical drive shaft 10. Records R used in connection with mydevice are preferably provided with an extraneous groove 11, leading into the usual sound record grooves, and an aperture 12, the latter being out of the field of record grooves. Furtherlocational characteristics of groove and aperture will be discussed later.

Attachment A includes a brush carrier 13, preferably made up of a disk of dielectric material, which is adapted 'to be removably supported on record B, there being provided means whereby the carrier and record are releasably held against relative rotation and lateral displacement so they revolve as one when the phonograph motor is operated. For instance, carrier 13 is threaded on a central spindle 14 having a coaxial socket 15 which opens downwardly to take the end of drive shaft 10, the carrier being thereby centered on the record. Flange 14 on spindle 14 bottoms in the countersink 15 of the carrier. Positioning pin 16 extends downwardly from the lower face of carrier 13 into record aper ture 12 and provides connective means whereby the carrier is drlven by record rotation.

Sunk below the upper face of carrier 13 is a closed conductor ring 17. A metal brush socket 18'is sunk in carrier 13 within ring 17 and is connected to said ring by conductor 19, which may be a short wire or a drop of solder. Brush 20 is slidably mounted in socket 18 and is adapted to be urged upwardly by spring 21. Angularly spaced brushes 22 are similarly mounted in sockets 18 but are."

Circular segmentplate 24 is so mounted on carr er 13 that plate and carrier are capable of relative rotation, but are held against relative vertical separative movement. For instance, plate 24 is threaded on a central bushing 25 having a running fit on spindle 14, nut 27' on this spindle serving to hold the carrier and plate detachably in assembly. Bushing 25 has end bearing at 26 on spindle flange 14. Plate 24 is preferably made up of'dielectric material and has a collector ring 28 sunk in its lower face, spring 21 serving to hold brush 20 in contact with ring 28 at all times. To one of the screws 29, which extends through plate 24 and holds the ring thereto, is connected wire 30 (see Figs. 7 and 11) from cable C. A plurality of commutator segments 31 to 38, inclusive, are individually held to the under face of plate 24 by screws 29*, being insulated from one another and so arranged that they are wiped successively by brushes 22 upon rotation of carrier 13.

The tubular member 39 of combination positioning arm and cable support 40 carries a y0ke .41, the yoke arms bein pivotally connected at their free ends to bridge-piece 40* (secured to plate 24 by screws40 by screws 42. The free extremity of tube 39 is adapted to extend between posts 43 on the relatively heavy anchoring block 44, the latter resting on top the phonograph. It will be seen that posts 43 hold member 40 and hence plate 24 from rotation about spindle 14, while the loose connection between tube 39 and the anchoring block, and the pivotal connection of yoke 41 with plate 24 allow the tube and plate such freedom of vertical movement with respect to each other and to the anchoring block as to permit the lower face of the brush carrier to remain in full facial contact with the disk record as the latter undulates during rotation.

Wires 31 to 38*, inclusive, extend from segments 31 to 38 in the manner illustrated in Fig. 7, and are gathered together to form cable C which extends through and is supported by tube 39. A cap 45 is removably held to plate 24 by nuts 46 and serves to cover and protect the segments and their wire connections. I

It will be evident from the above that with a properly prepared disk on the record table of any phonograph, attachment A may be operatively connected thereto by merely lowering it over the disk so shaft 10 and pin 16 enter sockets 15 and 12, respectively, and placing block 44 on top the phonograph, wit tube 39 extending between the posts 43.

Attachment B includes two casings 47 and 48 which are connected by sleeve 49, there being a shaft 50 extending through and having bearing in said sleeve. The opposite ends of the shaft project into casing compartments 47 a and 48". Casing 47 comprises a base plate 51 having angularly turned marginal flanges 52 to which is fastened a plate or panel 53 y of dielectric material. This panel is adapted to support the motor commutator which is made .up'of suitably insulated segments 31 to 38', inclusive, and a concentrically arranged collector ring 54 which is located within the circle of and insulated from the commutator segments. The segments and ring are shown to be held to panel 53 by screws 53' nd 54,

.and are individually connected by wires W,

in compartment 47 to segments 31 to 38'. l/Vires W may be considered, and I will so consider them, as extensions of Wires 31 to 38, since the two sets of wires are adapted to be detachably connected by binding posts 55 in the usual manner. It will thus be seen thata segment designated by a given numeral in the commutator of attachment A is connected by a wire having that number with an exponent a to a segment designated by that number primed.

Binding post 55 is connected to collector ring 54 by conductor strip 56, Wire 57 leading from said post to motor M. Wire 58 leads from the opposite side of motor M to a source 1:] of electricity, wire 30 from collector ring 28 of attachment A leading to the opposite side of source it).

Split block 57 is preferably clamped to the free ends of wires 57 and 31 to 38*, inelusive, serving to keep said wires properly arranged. when disconnected from the binding posts so they may be quickly reconnected without preliminary test.

'While it lies within thescope of my inven Lion, broadly considered, to construct arm 59 in any suitable manner, I have illustrated a preferable construction which I will now describe in some detail, it being borne in mind that while brushes 60 and 61 must pass current one to the other, the current must not be grounded by, shaft 50. Mounting plate 62 has a central hub 63 which carries a set screw h 64 for holding it non-rotatably on shaft 50.

Plate 62 may be extended to provide an indicator arm 64, the purpose of which will appear presently. Metal brush-plate 65 is secured to plate 62 by'screws 66 but is insulated therefrom by an intervening mica ring 67, the screw extending through insulating bushings 68. Plate 65 has a central aperture 69 which is of considerably greater diameter than hub 63, the clearance thus pro,

vided eliminating the chance of a ground be tween hub and brush-plate.

'At diametrically opposite points 70 plate 65 is forked, the metal ateach side of the fork openings being bent up to provide lips 71 between which extend metal brush holders 72. The holders'may be soldered or brazed to the lips in order tohold them rigidly'in position and to provide a proper electrical connection between plate 65 and brushes 60, 61, the latter being mounted for longitudinal movement within the holders. Springs 7 3 serve to press the brushes onto the contact elements on panel 53, as is evident from consideration of Fig. 13.

Shaft 50 carries bevel gear 74 which meshes with bevelgear 75 on shaft 76, the last named shaft being supported in the side walls of casing 18. Spur gear 77 is non-rotatably secured to gear 75 (it may be integral therewith) and meshes with spur pinion 78 fixedon tubular shaft 79. Shaft 79 extends through and is journalled in the side walls of casing 48 and carries at one end a knurled knob or hand wheel 80. The opposite endofshaft 79 extends beyond casing 48 and is provided with a key way 81.

Shaft 79 is adapted to be connected to the film advancing mechanism of the projector.

and through this mechanism to motor M, and while this connection may be made in any suitable manner without departing from the spirit and scope of my invention, I have provided a preferred means whereby connection may be made with a particular typeof projector without altering any of its film advanc ng mechanism. The film advancing mechanism I (not shown) of this projector is operated either by motor M through shaft S or by manual rotation of shaft 82 (Fi 2 and 16), shafts S and 82 being operative y connected through said mechanism so rotation of one causescoincident rotation'of the other. During normal operation, the advancing mechanism is driven by motor M, shaft 82 being manually operated only when threading the projector and testing out the mechanism. For this purpose is provided a knob (notshown) having a hollow shaft, the shaft slipping over the end of shaft 82 and engaging a key 83 thereon, a retaining screw (not shown) passing through the knob shaft and being threaded into the end of shaft 82. Should it be desired to operate the projector manually for a protracted period, a hand crank (not shown) is substituted for the knob.

T o attach my mechanism,.it is merely necessary to remove the standard hand knob and substitute shaft. 79, said shaft being slipped over the end of shaft 82 and into engagement with key 83v as shown in Fig. 16. A long screw 84 is then passed through shaft 79 and threaded into shaft 82. It follows that operation of motor M, in addition to causing operation of the film advancing mechanism, rotates shafts 79, 50 and brush arm 59. Or .manual operation of knob 80 causes rotation of arm 59 and coincidently operates the film advancing mechanism.

Casing 48 is thus suspended from shaft 82 and it remains only to support casing 47 I prefer to do this by means of a member e2 tending from the projector base and terminating in'a hookadapted to take'sleeve 4.9,

though this is not to be construed as limiting having a relatively large hole 86 through which extend, with considerable clearance, lantern feed wires 87. Supporting member 88 is in the form of a plate adapted to be laid on top wall 85 with one edge overlying the major portion of hole 86, leaving just enough room for the passage of Wires 87. Plate 88 has down-turned positioning lips 89 adapted to engage the side walls of the projector base. A locking head 90 has an upstanding, eccentrically located bolt 91 which extends through plate 88 and takes a wing or clamping nut 92 on its upper end. Head 90 also has a stop pin 93 which extends parallel to bolt 91 but is of no greater length than the thickness of top 85. y

In attaching plate 88 to the projector base, head 90 is turned through 180 from the position of Figs. 4c, 5 and 6 so it may be passed downwardly through hole 86, nut 92 being loosened sufiiciently' to drop the head below theunder face of top 85. The head is then rotated to the right until pin 93 engages the defining wall of the hole, bringing the head beneath top 85, whereupon nut 92 is screwed down tightly to clamp said top between plate 88 and head 90, thus firmly positioning the plate on the projector base. Plate 88 has a hook extension 94 adapted to support sleeve 49, though it allows the sleeve some freedom of movement so there may be no binding effect upon it.

I will now describe the operation of the device and in order to make this more clear, I will make certain assumptions as to speed ratios, numbers of-segment-s, etc., but these are to be considered merely as illustrative of and not in any way as restrictive on the invention. For instan'ce,..it will be assumed that the commutators of attachments A andB each have eight segments; that the brushes of the two attachments have clockwise movement (as viewed in 7) during normal operation; that each revolution of shaft 82 causes eight complete cycles of projector operation and rotates brush carrier 59 through 180 (causing brush 61 to traverse four commutator segments), and that when motor M is running at normal speedit tends to drive shaft 82 and 50 slightly faster than their speed of synchronism with the phonograph disk. I will assume that the two commutators, record and film are in proper starting position.

Sup ose now that the phonograph be starte record R rotating carrier 13 to cause brushes 22 tostart sweeping commutator segof a metal stamping, the top wall 85 thereof ment 31. Current then immediately flows through the following path; source E wire 30, ring 28, brush 20, ring 17, leading brush 22, segment 31, wire 31, segment 31, brush 61, plate 59, brush 60, ring 54, conductor 56, post 55*, wire 57, motor M and wire 58. The motor then starts operation and rotates shaft S to drive bot-h the film advancing mechanism of the projector and shaft 50 with its brush arm. Leading brush 22 is rotated by the phonograph motor to pass it onto segment 32, the current then flowing through wire 32* to the corresponding commutator segment 32' of attachment B. Now since motor M has a tendency to rotate shaft 50 a little faster than synchronous speed, brush 61 will have a tendency to reach segment 32 before leading brush 22 has reached segment 32; and accordingly the motor circuit has been broken before brush 22 reached said segment 32, the motor slowing down and not beginning again to operate at normal speed until said segment 32 is reached by leading brush 22. A corresponding action takes place asthe brushes pass successively over the several segments, synchronism bemg thus restored eight times during each revolution of shafts 50 and 10. By proper choice of gear ratios, driving speeds, numbers of commutator segments,

-etc., the two attachments may be arranged to restore. synchronism at other predetere mined intervals. Ordinarily, however, the ratio 1 bet-ween the numbers of commutator segments and numbers of cycles of projector operation (or exposures made by the projector) per revolution of operating shaft should be such that one numberis evenly divisible by the other so the same number of complete motor impulses will always occur during a given number of complete cycles of projector operation.

With the assumption made above to the effect that during eight complete cycles of projector operation, brush 61 traverses four commutator segments, it will be seen that synchronism is restored once during each alternate cycle of pro'ector operation.

There are mar ings provided whereby the brushes of attachments A and B may be initially set over corresponding segments of their respective commutators so, without experimentation, it is assured that the operating circuit between commutators is closed when reproduction is to start. For instance, there is a mark 100 on disk R in predetermined angular relation to aperture 12 (in diametrical opposed relation, for example) and the start '11 of extraneous groove'll may be in line with mark 100 and aperture 12. By reason of pre-arrangement made at the time of recordation on the original film and blank dlsk when pin 16 is 'n record aperture 12, the reproduction nee le 17 of the phonograph 1n groove 11 at 11, and arm 39 immediately overlying mark 100; and with mark 101 on indicator arm 64 opposite mark 102 on panel 53 (see Fig. 7), it 1s assured that brushes 22 and 61 are on corresponding segments of the attachment commutators. Hand wheel .80 provides means for manually rotating brush arm 59 to bring it into correct starting position as indicated by the matching of marks 101, 102.

The starting point of the original film is marked to correspond with the starting point of the originally blank disk, so the film through which projection is made and the record disk may be initiall set in corresponding starting positions. he initial soundless run of the needle through groove 11 gives the mechanisms an opportunity to come up to speed before actual recording'or reproduction begins; and the film likewise will plurality of commutator segments, and a brush carrying member associated with the commutator member, said members being capable of relative rotation, such rotation being adapted to cause the brushes provided on said carrying member to contact successively with the commutator segments, one of said members being adapted to rest on top the disk and being drivmgly connected thereto, and .means supportable on the phonograph adapted to hold the other member against rotation; said last named means having oints in it to allow said commutator and rush carrying member'to undulate with the disk during rotation of thelatter.

2. In a motor synchronizing control adapted to be operated by a phonograph disk, an

attachment for the disk that includes a brush carrier adapted to be supported on the disk in coaxial relation thereto, means for drivingly connecting the carrierand disk, a commutator plate, said carrier supporting and being capable of rotation relative to the plate, a collector ring and aconcentric ring of commutator segments on said plate, a pair of electrically connected brushes on said carrier, one of the brushes being adapted to wipe the collector ring, and the other being adapted to Wipe the segments successively upon relative rotation. of the carrier and plate, and an arm connected at one end to said plate and adapted to be supported near its other end to the phonograph in a manner to hold said plate against rotation. I

3. In a motor synchronizing control adapted to be operated by a phonograph disk, an

attachment for the disk that includes a brush a collector ring and a concentric ring of commutator segments on said plate, a pair of electrically connected brushes on said carrier one of the brushes being adapted to wipe the collector ring and the other brush being adapted to wipe the segments successively upon relative rotation of the carrier and plate,

- and an arm pivotally connected at one end to said plate and adapted to be supported near its other end to the phonograph case in a manner to hold said plate against rotation 4. In a motor synchronizing control adapted to be operated by a phonograph disk, an attachment for the disk that includes a brush carrier adapted to be supported on the disk in coaxial relation thereto, a central, vertical spindle on the carrier and having a coaxial socket adapted to take the end of the phonograph drive shaft, means for drivingly connecting the carrier and disk, a commutator plate, said carrier supporting and being capable of rotation relative to the plate, acollector ring and a concentric ring of commutator segments on said plate, a pair of electrically connected brushes on said carrier, one of saidbrushes being adapted to wipe the collector ring and the other brush being adapted to wipe the segments successively upon relative rotation of the carrier and plate, and an arm connected at one end to said plate and adapted to be supported near its other end to the phonograph in a manner to hold said plate against rotation.

5. In a motor synchronizing control adaptattachment for the disk that includes a brushv carrler adapted to be supported on the diskin 'coaxial relation thereto, means for drivingly connecting the carrier and disk, acommutator plate supported on the carrier, a central bushing extending vertically through said plate and rotatably mounting the plate on said spindle, means on the spindle adapted to hold the carrier and plate from vertical separative movement, a collector ring and a concentric ring of commutator segments on said plate, a pair of electrically connected brushes on said carrier, one of said brushes being adapted to wipe the collector ring and the other brush being adapted to wipe the segments successively upon relative rotation of the carrier and plate, and an arm connected at one end to said plate and adapted to be supported near'its other end on the phonograph in a manner to hold said plate against rotation.

ed to be operated by a phonograph disk, an

6. In a device of the character described, a controlling commutator comprising two disk-like members relatively rotatable about a common central axis, one of said members bein adapted to rest on a phonograph disk and be rotated thereby, the other restin'g upon the one, cooperating electrical contacts carried by the two disks, and the upper one of said disks having a projecting arm adapted to act as an anchor against rotation.

7. In a device for synchronizin a motor and a phonograph disk, a control ing commutator having two relatively rotatable parts, one of which is adapted to rest on the disk and be driven thereby, the other having an extending arm,, and shiftably adjustable means to hold said arm from rotation with the disk while allowing movements to accommodate undulations with the disk.

In witness that I claim the foregoing I; 

